For questions about using a browser add-on with a specific web application.
Browser add-ons (sometimes called "extensions") are small pieces of functionality that can be added to web browsers, often by third-parties. They offer some extra functionality that the web browser, by itself, does not have. It can be general or very specific.
For the most part, questions about browser add-ons are off-topic on Web Applications, and should instead be asked at Super User.
If your question is about how a browser add-on interacts with a specific web application, or it may be on-topic here.